There was something odd about my new patient. She was elegantly dressed and self-possessed, and yet she was slowly, rhythmically chewing gum, something I rarely see in my psychiatry sessions. Was she trying to cover up anxiety about this first encounter, I wondered, or was she perhaps hoping to project a kind of cool, laid-back style?
We talked for a long time about why she had come to see me. Then, as is my practice with a new patient, I asked what, if any, psychiatric medications and non-prescription, psychoactive substances - legal or illegal - she had used. Her answer was a new one for me. She stated that she chewed approximately 40 pieces of nicotine gum per day and had done so for well over a decade.
Responses to this question are often illuminating and can be rather humbling. Although doctors are trained to focus on prescription medications, there are and have always been non-prescription "remedies" for psychiatric conditions. And people's preferences for one type of substance over another can give a glimpse into their symptoms and even their brain chemistry.
If a patient tells me he falls asleep on cocaine, I wonder if he might have attention deficit disorder. A patient who smokes marijuana to calm down before important business meetings leads me in the direction of social phobia or other anxiety disorders. I often wonder if people who take ketamine recreationally might be depressed, since this anaesthetic has been shown to have antidepressant effects and is, in fact, being investigated for potential therapeutic use.
Sorting through patients' uses of psychoactive substances, from cocaine to alcohol to coffee, leaves me with an appreciation of the wildly different neurochemistry of people's brains. One person will drink alcohol and feel euphoric, witty and extroverted, and the next will be sluggish and nauseated. In one patient, marijuana sharpened his focus and made it possible to pay attention in class, hugely improving his grades. Another felt paranoid and a third used it as a sleep aid. And presumably these substances all hit the same brain receptors in each of them.
My new patient explained that in her sophomore year at college, she had started smoking. The effect, she said, was like "a key that fit perfectly into a lock". Her brain felt clearer, her thoughts were more coherent, her mood and energy improved. Not wanting to damage her lungs, she soon switched over to nicotine gum and had been taking the same amount of it for well over a decade - a pattern of stable "dosing" that I discovered is typical in long-term nicotine users.
She asked me what I thought of her use of the drug. The short answer was that I didn't know what to make of it.
But as I thought about our conversation later, I found her image of a key in a lock particularly striking; it was the very same one that psychiatrists and neurophysiologists use to describe the interactions in the brain between neurotransmitters and their receptors.
And in fact, neurons do have receptors into which nicotine neatly fits, mimicking the actions of the brain's own molecules.
Did the patient lack the neurotransmitter that normally stimulates these receptors? If so, perhaps nicotine was an effective treatment. Research has confirmed my patient's experience of the positive psychiatric effects of nicotine: It has been shown to improve cognition, memory, attention and mood, as well as reduce anxiety. People with serious mental illnesses, particularly schizophrenia and depression, smoke at much higher rates than people without them and have more difficulty quitting - perhaps because nicotine ameliorates some of their symptoms. Oddly, there may even be health benefits from smoking: Smokers have lower rates of Parkinson's disease. (Of course, this doesn't outweigh the risks.) Maybe my patient was simply describing an addiction. We don't know how addictive nicotine gum is. Like the nicotine patch, it delivers nicotine to the bloodstream and therefore to the brain at a much slower rate and with lower peak blood levels than cigarettes. This steadier, lower level of nicotine makes the gum much less addictive.
My patient craved nicotine and went to great lengths to make sure she had the exact supply she needed at all times. It is certainly possible that if she tried to stop it, she would experience some type of withdrawal. And yet, in the current Diagnostic and Statistical Manual of Mental Disorders, the DSM-5, an addiction (or, to use the official term, a "substance-use disorder") can cause "such an intense activation of the reward system that normal activities may be neglected". This woman - married, with a child, friends and a successful career - was certainly not neglecting "normal activities". The real question was not whether my patient should start taking nicotine and risk becoming addicted, but what to do now that she was on it. Was she endangering her health?
The research literature, as is so often the case, was unclear. Nicotine, in part through the release of adrenaline, can increase heart rate and blood pressure.
Although animal studies have raised the possibility that these changes may damage the blood vessels, potentially leading to cardiovascular disease, the limited data in humans has not confirmed this risk.
Cigarettes, on the other hand, include many other substances that act in concert with nicotine to damage blood vessels, and the risk to cardiovascular health from smoking is clear. I called several experts in the field and they all agreed that there are no well-documented serious harmful effects of non-tobacco nicotine products - other than addiction.
In other words, nicotine is like most of the medications I prescribe. Nearly all involve risks and in some, such as Ritalin, Adderall and other stimulants, many of the side effects are nearly identical to those of nicotine, including potential addiction. For some patients, a medication can lead to nearly miraculous improvements. For others, the benefits are modest. And the side effects can involve serious health issues.
So how did I answer my patient's question? We discussed my findings. Long-term consequences, including possible heart problems, could not be ruled out. Ultimately, she was the one who had to make the decision. I did not feel strongly that she needed to stop and, perhaps not surprisingly, she didn't.
Several days after our discussion, curious about this interesting substance, I walked into my local drugstore and purchased nicotine gum. It felt like an illicit transaction as the pharmacist produced it from under the counter. Minutes after popping a tab into my mouth, I felt as if I'd consumed a pitcher of high-octane coffee.
It was yet another lesson in how little we know about individual brain chemistry. One person's pharmacologic boon is another's pharmacologic debacle. What left my patient calm and serene gave me a shaky, unsettled feeling. I walked in the park for an hour before sitting down in a cafe and ordering a glass of wine. I needed something to steady my nerves.
NEW YORK TIMES
The writer is a psychiatrist and faculty member at Weill Cornell Medical College in New York.
A version of this article appeared in the print edition of The Sunday Times on March 20, 2016, with the headline 'Can nicotine be good for you?'. Print Edition | Subscribe
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